Add "Header manipulation rules" to mirrors

[mikulskibartosz]

Hi,
Can the mirror destination be updated to support "headers" (for Header manipulation rules)?

Describe the feature request

From the user perspective, it would look like using the HTTPRouteDestination in the mirror attribute (and inside of HTTPMirrorPolicy) instead of a Destination.

We need this feature because we use the headers modified by Istio as a source of labels for monitoring. All shadow traffic comes without labels and cannot be adequately monitored.

Describe alternatives you've considered

As a workaround, we set some headers at the HTTPRoute level and more detailed information in the headers at the HTTPRouteDestination level. Then, use a lack of detailed headers to indicate a mirror destination. It's not ideal because we cannot distinguish between individual instances of the mirror when we deploy a new version.

Affected product area (please put an X in all that apply)

[ ] Ambient
[ ] Docs
[ ] Dual Stack
[ ] Installation
[X] Networking
[ ] Performance and Scalability
[ ] Extensions and Telemetry
[ ] Security
[ ] Test and Release
[ ] User Experience
[ ] Developer Infrastructure

Affected features (please put an X in all that apply)

[ ] Multi Cluster
[ ] Virtual Machine
[ ] Multi Control Plane

Additional context